JPH11210619A - Swash type variable displacement compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To materialize a structure for promptly changing the quantity of refrigerant vapor compressed for every rotation of a driving shaft by corresponding to a change in a refrigerant load and a change in the rotating speed of the driving shaft. SOLUTION: Both the ends of a guide pin 32a are provided at a pair of driven arms 31a, 31a at their tip parts and are rotatably supported in each circular holes 47, 47 through radial needle bearings 48, 48. The intermediate part of the guide pin 32a is penetrated in the inclined long hole 30 of a driving arm 29. In order to change the quantity of refrigerant vapor compressed for every rotation of a driving shaft, in changing the inclination of a swash plate, rolling contact is applied to the outer boundary face of the guide pin 32a and the inside face of the inclined long hole 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A swash plate type variable displacement compressor according to the present invention is incorporated in an automotive air conditioner for cooling and dehumidifying a vehicle interior, compressing refrigerant sucked from an evaporator, and then compressing the refrigerant. Discharge toward.

[0002]

2. Description of the Related Art A vapor compression refrigerator incorporated in an air conditioner for a vehicle is configured as schematically shown in FIG. The compressor 1 compresses the refrigerant vapor sucked from the suction port and then discharges the compressed refrigerant vapor from the discharge port. This compressor 1
The refrigerant discharged from is condensed by radiating heat by performing heat exchange with air while passing through the condenser 2.
The liquid refrigerant discharged from the condenser 2 passes through the liquid tank 3 and the expansion valve 4 and then passes through the evaporator 5.
And evaporates in the evaporator 5. Since the temperature of the evaporator 5 is reduced by the evaporation of the refrigerant inside, the air passing through the evaporator 5 is cooled, and the cooling and dehumidification of the interior of the automobile can be performed. The refrigerant evaporated in the evaporator 5 is sucked into the compressor 1 from the suction port.

[0003] As the compressor 1 constituting a vapor compression refrigerator incorporated in such an air conditioner for a vehicle, various types of structures are conventionally known. In addition, a swash plate type in which the rotational motion of the drive shaft is converted into a reciprocating motion of a piston by a swash plate, and the piston compresses the refrigerant, and
Variable displacement compressors capable of adjusting the discharge amount per rotation have been widely known. Figs. 5 and 6 show an example of such a swash plate type variable displacement compressor described in Japanese Patent Publication No. 64-1668.
5 and 6, FIG. 5 shows a state in which the capacity is maximized, and FIG. 6 shows a state in which the capacity is also minimized. First, the conventional swash plate type variable displacement compressor shown in FIGS. 5 and 6 will be described.

[0004] A casing 6 constituting the compressor 1
Is to connect the center casing body 7 to the head case 8 and the end plate 9
5 and 6 from both sides in the axial direction (left and right directions in FIGS. 5 and 6), and further connected by a plurality of connecting bolts (not shown). Inside the head case 8 is a low-pressure chamber 1
0 and 10 and a high-pressure chamber 11 are provided. The high pressure chamber 11
The pressure inside the low-pressure chamber 10 is, of course, positive pressure. Further, a flat partition plate 15 is sandwiched between the casing body 7 and the head case 8. The low-pressure chambers 10, which are divided into a plurality of parts in FIGS. 5 and 6, communicate with each other and communicate with a single suction port 12 a provided on the outer surface of the head case 8. . The high-pressure chamber 11 also communicates with a discharge port 12b provided in the head case 8. And, the suction port 12
a is connected to the outlet of the evaporator 5 (FIG. 4), and the discharge port 12b is connected to the inlet of the condenser 2 (FIG. 4).

A drive shaft 13 is supported in the casing 6 so as to freely rotate only in a state of being bridged between the casing body 7 and the end plate 9. That is, both ends of the drive shaft 13 are supported on the casing body 7 and the end plate 9 by a pair of radial needle bearings 22a and 22b, and the drive shaft 13 is supported by a pair of thrust needle bearings 23a and 23b. The thrust load applied to the can be supported freely. These one pair of thrust needle bearings 23a,
One of the thrust needle bearings 23a (the right one in FIGS. 5 to 6) is formed between the adjustment nut 24 and a step 25 formed at one end of the drive shaft 13 (the right end in FIGS. 5 to 6). Is provided. The adjusting nut 24 is screwed into a female screw portion formed in the center hole 26 of the casing body 7 so that the axial position can be adjusted. The other thrust needle bearing 23b (left side in FIGS. 5 and 6) is provided between a support bracket 20 described later and the end plate 9. A plurality of cylinders 14 (for example, five to six at equal intervals in the circumferential direction, only one is shown in the drawing) are formed inside the casing 6 around the drive shaft 13. The pistons 16 are respectively fitted to the inside of the plurality of cylinders 14 formed in the casing body 7 so as to be displaceable in the axial direction.

Further, inside a part of the casing body 7,
A portion between the portion where the plurality of cylinders 14 are formed and the end plate 9 is a crank chamber 18. Further, a sleeve 19 and a support bracket 20 are provided in the middle portion of the drive shaft 13 in a portion located in the crank chamber 18 in order from the side where the cylinder 14 is provided. The sleeve 19 has an outer surface 19a (outer surface) having a spherical convex surface and an inner surface (inner surface) having a cylindrical surface. In addition, the inner diameter surface is slidable with respect to the drive shaft 13. Further, the support bracket 20 is externally fitted and fixed to the drive shaft 13 so as to rotate together with the drive shaft 13. In addition, between one end surface of the sleeve 19 (left end surface in FIGS. 5 and 6) and one side surface (lower end portion in FIGS. 5 and 6) of the support bracket 20 (right side surface in FIGS. 5 and 6). Is provided with a compression spring 21 to impart elasticity to the sleeve 19 in a direction approaching the cylinder 14. Therefore, unless a force acts on the swash plate 27 described below, the sleeve 19 is displaced toward the cylinder 14 until it abuts against the stop ring 28 as shown in FIG. (The inclination angle with respect to the drive shaft 13 increases. In other words, the inclination angle θ of the swash plate 27 with respect to the virtual plane perpendicular to the drive shaft 13 decreases). Further, when a clutch is not used to bring the compressor 1 into a non-operating state, the swash plate 27 may be formed at right angles to the drive shaft 13.

[0007] The inner diameter of the swash plate 27 is fitted to the sleeve 19 so as to swing freely. That is, the inner diameter surface 27a (inner peripheral surface) of the swash plate 27 is
9a is a spherical concave surface having substantially the same curvature. The swash plate 27 is supported around the drive shaft 13 so as to be freely adjustable in axial displacement and inclination by fitting the inner diameter surface 27a to the outer diameter surface 19a in a slidable manner. doing.

A drive arm 29 is provided on the outer peripheral edge of the support bracket 20 (upper edge in FIGS. 5 to 6) so as to protrude outward in the diameter direction. An inclined slot 30 is formed at the tip of the drive arm 29 in a direction substantially perpendicular to the axial direction of the drive shaft 13 (vertical direction in FIGS. 5 and 6).
On the other hand, a driven arm 31 is fixed to a portion of the swash plate 27 that faces the driving arm 29 on one surface (the left surface in FIGS. 5 and 6). A guide pin 32 is provided at the tip of the driven arm 31.
Are formed in the direction of twist with respect to the drive shaft 13.
The guide pins 32 pivotally support the swash plate 27 so that the inclination angle can be adjusted by loosely fitting into the oblong slot 30. That is, the swash plate 27 slides on the drive shaft 13 and slides the sleeve 19, so that the guide pin 32
Rocking around.

For example, when the sleeve 19 is a compression spring 21
In a state in which the guide pin 32 approaches the support bracket 20 against the elasticity of the above, the guide pin 32 is located at the outer end (in the diametric direction about the drive shaft 13) of the oblong slot 30 as shown in FIG. Moving. In this state, the inclination angle θ of the swash plate 27 with respect to an imaginary plane orthogonal to the drive shaft 13 increases, and the piston 1
6, the stroke of the compressor 1 is increased. On the other hand, the sleeve 19 has the compression spring 2
In a state in which the guide pin 32 moves away from the support bracket 20 based on the elasticity of 1, the guide pin 32 moves to the inner end of the inclined oblong hole 30 as shown in FIG. In this state, the inclination angle θ becomes small, the stroke of each of the pistons 16 associated with the rotation of the drive shaft 13 becomes short, and the capacity of the compressor 1 decreases.

A plurality of swash plates 27 supported around the drive shaft 13 in the circumferential direction and the pistons 16
Is a pair of sliding shoes 17,
17 are connected. The inner surfaces (surfaces facing each other) of each of the sliding shoes 17, 17 are flat surfaces and are in sliding contact with the outer diameter portions of both sides of the swash plate 27. The outer surfaces of the sliding shoes 17, 17 (the side opposite to the mating sliding shoe 17) are spherical convex surfaces. And, the swash plate 2
The outer surfaces of the two sliding shoes 17, 17 are positioned on a single spherical surface in a state of contact with both side surfaces of the sliding shoe 7. On the other hand, at the rear end of each of the pistons 16 (an end farther from the partition plate 15 and at the left end in FIGS. 5 to 6), a connecting arm portion 34 which constitutes a transmission member together with the sliding shoes 17, 17 is provided. Are formed integrally with each piston 16. A holding portion 33 for holding the pair of sliding shoes 17, 17 is formed in each connecting arm portion 34. The holding portion 33 is formed with spherical concave surfaces 35, 35 slidably contacting the outer surfaces of the sliding shoes 17, 17 so as to face each other.

A part of the inner peripheral surface of the casing main body 7 that is aligned with the outer end of each of the connecting arms 34 includes:
One pair of guide surfaces 36 for each piston 16
Are formed to be spaced apart in the circumferential direction. The circumferential edge of the outer end of each of the connecting arms 34 is guided by the guide surface 36 so that only the displacement of the piston 16 in the axial direction (the left-right direction in FIGS. 5 and 6) is possible. Therefore, each of the pistons 16 is also fitted into the cylinder 14 so that only the displacement in the axial direction is possible (rotation is impossible). As a result,
The connecting arms 34 push and pull the pistons 16 in accordance with the swing displacement of the swash plate 27, and reciprocate the pistons 16 in the cylinder 14 in the axial direction.

On the other hand, in order to partition the low pressure chamber 10 and the high pressure chamber 11 from the cylinders 14, the partition plate 15 sandwiched between the butting portions of the casing body 7 and the head case 8 has the low pressure chamber 10 And a suction port 37 for communicating the cylinder 14 with the high-pressure chamber 11 and the cylinder 14. A suction valve 39 for flowing refrigerant vapor only from the low-pressure chamber 10 toward each of the cylinders 14 is provided in the suction port 37 of the above. Further, a discharge valve 40 for flowing refrigerant vapor only from each of the cylinders 14 toward the high-pressure chamber 11 is provided at the discharge port 38. These suction valves 39
The discharge valve 40 generally uses a reed valve as shown.

The low-pressure chamber 10 and the crank chamber 18
A pressure adjusting passage 41 is provided between the two chambers 10 and 18 so as to communicate with each other. A pressure control valve 45 is provided in the pressure control passage 41. The pressure adjusting valve 45 includes a bellows 42 that expands and contracts in the axial direction according to the surrounding pressure, and a needle 44 that opens and closes the communication hole 43 as the bellows 42 expands and contracts.
Then, according to the refrigerant pressure in the low-pressure chamber 10 that changes with a change in the cooling load, opening and closing of the pressure adjustment passage 41,
Alternatively, the opening is adjusted. The bellows 42 is hermetically sealed with a gas at a predetermined pressure sealed therein.

The operation of the conventional variable displacement compressor 1 configured as described above is as follows. When operating a vapor compression refrigerator to cool or dehumidify the interior of the automobile, the drive shaft 13 is driven to rotate. As a result, the swash plate 27 rotates and the plurality of pistons 16
Are reciprocated in the cylinder 14 respectively. And
As the piston 16 reciprocates, the refrigerant vapor in the low-pressure chamber 10 communicating with the suction port 12a is sucked into the cylinder 14 through the suction port 37. The refrigerant vapor is then compressed in the cylinder 14 and then sent out to the high-pressure chamber 11 through the discharge port 38.

When the cooling load is large and a large amount of refrigerant vapor needs to be compressed by the compressor 1, the pressure of the refrigerant vapor sent from the evaporator 5 (FIG. 4) to the low-pressure chamber 10 increases. The pressure in the pressure adjustment passage 41 communicating with the low-pressure chamber 10 also increases. In this state,
The bellows 42 constituting the pressure regulating valve 45 contracts, and the needle 44 retreats from the flow hole 43. As a result, the crank chamber 18 is connected to the communication hole 43 and the pressure adjustment passage 41.
, The pressure in the crank chamber 18 decreases.

The pressure in the crank chamber 18 is
It joins the rear surface of the plurality of pistons 16 (left surface in FIGS. 5 and 6). On the other hand, the pressure in the compression space of the cylinder 14 (the space between the front surface of the piston 16 and the partition plate 15) is applied to the front surface (the right surface in FIGS. 5 and 6) of each of the pistons 16. Accordingly, each of the pistons 16 tends to be pushed to a lower pressure side by a force corresponding to a difference between the pressure in the crank chamber 18 and the pressure in the compression space. Then, the sum of these forces applied to each piston 16 is applied in a direction in which the inclination angle of the swash plate 27 is changed. Of course,
Although the pressure in the compression space changes according to the stroke of the piston 16, the reciprocation of the piston 16 is performed at a high speed.
The pressure in the compression space can be considered as an average value of all the strokes. Therefore, when the pressure in the crank chamber 18 is reduced as described above, the pressure in the crank chamber 18 is sufficiently lower than the pressure in the compression space, and the pistons 16 are connected to the swash plate 27. In FIGS. 5 and 6, the force of pressing leftward is increased.

On the other hand, as described above, the guide pin 32, which is a pivot for pivotally supporting the swash plate 27, is provided at a position displaced radially outward from the center of the drive shaft 13. For this reason, the moment when each piston 16 presses the swash plate 27 differs for each piston 16, and is small for the piston 16 near the guide pin 32 and large for the piston 16 far from the guide pin 32. Therefore, when the pressure in the crank chamber 18 is low, the side of the swash plate 27 that is far from the guide pin 32 is greatly inclined away from the cylinder 14 as shown in FIG. 5 (the inclination angle θ becomes large). . As a result, the stroke of each piston 16 accompanying the rotation of the swash plate 27 increases, and the capacity of the compressor 1 increases.

On the other hand, if the cooling load is small and the amount of refrigerant vapor discharged from the compressor 1 is small, the evaporator 5 (FIG. 4) can supply the low-pressure chamber 10
The pressure of the refrigerant vapor sent to the low pressure chamber 10 decreases, and the pressure in the pressure adjustment passage 41 communicating with the low pressure chamber 10 also decreases. In this state, the bellows 4 constituting the pressure regulating valve 45
2 extends, and the tip of the needle 44 enters the flow hole 43. As a result, the communication between the crank chamber 18 and the low-pressure chamber 10 is cut off. Since high-pressure refrigerant vapor (blow-by gas) leaking from a gap between the outer peripheral surface of the piston 16 and the inner peripheral surface of the cylinder 14 gradually enters into the crank chamber 18, the crank chamber 18 When the communication between the low pressure chamber 18 and the low pressure chamber 10 is cut off, the crank chamber 1
The pressure in 8 rises.

When the pressure in the crank chamber 18 is high, the pressure in the crank chamber 18 is higher than the pressure in the compression space, and the piston 1
5 and 6, the force of pressing rightward in FIG. Therefore, as shown in FIG. 6, the swash plate 27 is close to being perpendicular to the drive shaft 13 (the inclination angle θ is small). As a result, the stroke of each of the pistons 16 associated with the rotation of the swash plate 27 decreases, and the capacity of the compressor 1 decreases. When the cooling load is intermediate, the pressure regulating valve 45 adjusts the pressure in the crank chamber 18 to approximately the intermediate level, and the inclination angle θ of the swash plate 27 is shown in FIG. 5 and FIG. Regulate in the middle of the state.

[0020]

SUMMARY OF THE INVENTION Cooling load or drive shaft 1
In order to stably control the temperature of the passenger compartment even when the rotation speed of the drive shaft 3 changes, the cooling load or the drive shaft 1 must be controlled.
It is necessary to quickly change the amount of the refrigerant vapor compressed by the compressor 1 in accordance with the change in the rotation speed of the compressor 3. However, in the case of the above-described conventional structure, it was difficult to quickly change the amount of refrigerant vapor compressed by the compressor 1 in this manner. The reason is as follows. That is, when changing the amount of refrigerant vapor compressed by the compressor 1, the inclination angle of the swash plate 27 is changed as described above. However, when the guide pins 32 are moved in the oblong holes 30 as described above in order to change the inclination angle of the swash plate 27, the outer peripheral surfaces of the guide pins 32 and the inner surfaces of the oblong holes 30 are changed. Large friction force (sliding friction force)
Works.

That is, the oblong slot 30 is connected to the drive shaft 1.
3 is formed in a direction (vertical direction in FIGS. 5 and 6) crossing the axial direction (horizontal direction in FIGS. 5 and 6). Further, the axial thrust load is applied to the swash plate 27 from each piston 16. Therefore, when the inclination angle of the swash plate 27 changes, the guide pin 32 moves in the oblong slot 30 while being strongly pressed against the inner edge of the oblong slot 30. Therefore, the guide pin 32 is not
When moving within zero, a large frictional force (sliding frictional force) acts between the outer peripheral surface of the guide pin 32 and the inner side surface of the oblique long hole 30. Such a frictional force becomes a resistance to changing the inclination angle of the swash plate 27. Because of this,
In the case of the conventional structure, the cooling load or the drive shaft 13
It is difficult to quickly change the amount of the refrigerant vapor compressed by the compressor 1 in accordance with the change in the number of revolutions.

FIG. 7 shows the results of an experiment conducted by the present inventor to confirm whether or not the followability of the swash plate 27 in the above-described conventional structure is good. In this experiment, the drive shaft 13 of the compressor 1 incorporated in the vapor compression refrigerator (FIG. 4) was assumed on the assumption that the vehicle accelerated rapidly on a highway or the like.
When the rotational speed of the swash plate 27 suddenly increased, the followability of the swash plate 27 was measured. In this experiment, in order to measure the followability of the swash plate 27, the change in the actual inclination angle of the swash plate 27 was not directly observed, but instead the flow from the evaporator 5 (FIG. 4) was introduced into the compressor 1. The followability of the swash plate 27 was evaluated by measuring the temperature of the refrigerant vapor. In FIG. 7, the solid line a indicates the compressor 1
, The broken line b indicates the temperature of the refrigerant vapor sucked from the evaporator 5 into the compressor 1, and the dashed line c indicates the pressure of the refrigerant vapor sucked from the evaporator 5 into the compressor 1. , Two-dot chain line d
Represents the pressure of the refrigerant vapor projected from the compressor 1 to the condenser 2 (FIG. 4). FIG.
As can be seen from FIG. 5, when the rotation speed of the drive shaft 13 indicated by the solid line a is rapidly increased from 900 (rpm) to 4000 (rpm), the refrigerant drawn into the compressor 1 from the evaporator 5 indicated by the broken line b The temperature of the steam temporarily rose from -1 ° C to + 6 ° C, and then returned to the pre-rise temperature of -1 ° C. As a result of the measurement, the time from the rise of the temperature of the refrigerant vapor to the return to the original temperature (temperature change time T) was 78 (sec). From this result, it can be understood that the swash plate 27 cannot be said to have good followability in the case of the conventional structure. The swash plate type variable displacement compressor of the present invention has been invented in view of the above circumstances.

[0023]

The swash plate type variable displacement compressor according to the present invention is provided with a casing having an intake port and a discharge port, and is provided in the casing, similarly to the above-mentioned conventional swash plate type variable displacement compressor. A low-pressure chamber communicating with the suction port, a high-pressure chamber provided in the casing and communicating with the discharge port, a drive shaft rotatably supported in the casing, and a periphery of the drive shaft inside the casing. A plurality of cylinders each formed substantially parallel to the drive shaft, a piston axially displaceably fitted inside each of the cylinders, and an intermediate portion of the drive shaft. A swash plate supported by the drive shaft and rotating together with the drive shaft; an angle adjusting means capable of adjusting the inclination angle of the swash plate; and a swash plate associated with the rotation of the drive shaft. A transmission member for transmitting the displacement of the drive shaft in the axial direction to each of the pistons; a suction valve for flowing refrigerant vapor only from the low-pressure chamber to each of the cylinders; and only from the cylinders to the high-pressure chamber. A discharge valve through which refrigerant vapor flows. The angle adjusting means includes a drive arm rotatably supported on the drive shaft together with the drive shaft, and a driven arm fixed to a portion of the swash plate opposite to the drive arm on one side surface. And an oblong slot formed at the tip of one of the drive arm and the driven arm. Further, a pair of the other arm of the driving arm and the driven arm is provided, and the one arm is sandwiched by the pair of the other arms from both sides, and the tip of the other arm is supported. An intermediate portion of the guide pin is inserted into the oblong hole. And when adjusting the inclination angle of the swash plate,
While displacing the support portion of the swash plate with respect to the drive shaft in the axial direction of the drive shaft, while moving the intermediate portion of the guide pin in the inclined slot in the longitudinal direction of the inclined slot, The swash plate is swung about the guide pin. In particular, in the swash plate type variable displacement compressor of the present invention, the inner surface of the oblong slot is in rolling contact with the cylindrical surface concentric with the guide pin.

[0024]

The swash plate type variable displacement compressor of the present invention configured as described above compresses the refrigerant sucked from the suction port and discharges it from the discharge port. The same is true. In particular, in the case of the swash plate type variable displacement compressor of the present invention, even when the cooling load or the rotation speed of the drive shaft changes, and the amount of refrigerant vapor to be compressed by the compressor changes, one rotation of the drive shaft can be achieved. It is possible to quickly change the amount of refrigerant vapor to be compressed per hit. That is, in order to change the amount of the refrigerant vapor to be compressed in this way, to change the inclination angle of the swash plate, when the guide pin moves in the inclined long hole, The guide pin and the concentric cylindrical surface are in rolling contact. Therefore, the frictional force (rolling frictional force) acting on the contact portion between the inner side surface of the oblique slot and the concentric cylindrical surface.
Becomes very small. Accordingly, the degree to which the frictional force becomes a resistance when the inclination angle of the swash plate changes is extremely small, and the inclination angle of the swash plate can be changed quickly (improvement of followability). As a result, even when the refrigerant load or the rotation speed of the drive shaft changes, the amount of refrigerant vapor to be compressed can be changed quickly.

[0025]

1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. FIG. still,
The feature of this example is that when the amount of refrigerant vapor compressed by the compressor is changed, the guide pin 32a and the oblong slot 30 are connected to each other so as to smoothly change the inclination angle of the swash plate 27 (see FIGS. 5 to 6). The point is that the structure of the engaging portion is devised. Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIGS. 5 and 6, overlapping illustration and description will be omitted or simplified. The description will focus on the parts.

A pair of driven arms 31a, 3a is provided on one side of a base 46 which is fixedly connected to one side of the swash plate 27 (the left side in FIGS. 5 and 6).
1a are fixedly arranged at a distance from each other. or,
The distal end of the drive arm 29 protruding from the outer peripheral edge of the support bracket 20 (see FIGS. 5 and 6) is loosely inserted between the driven arms 31a and 31a. An inclined slot 30 is formed at the tip end of the drive arm 29 in a direction crossing the axial direction of the drive shaft 13 (see FIGS. 5 and 6) (the front and back direction in FIG. 1). And, the inclined oblong hole 30
, An intermediate portion of the guide pin 32a is inserted. on the other hand,
Circular holes 47, 47 are formed at the tips of the pair of driven arms 31a, 31a, respectively. Then, both ends of the guide pin 32a are inserted into these circular holes 47, 47, respectively.
The guide pins 32a are rotatably supported by the pair of driven arms 31a, 31a by being supported via radial needle bearings 48, 48, respectively.

Each of the above radial needle bearings 48, 48
A cylindrical outer ring 49 fitted and fixed in each of the circular holes 47, 47; a plurality of needles 50, 50 arranged circumferentially on an inner diameter side of the outer ring 49; And a ring-shaped retainer 51 for holding the rollers 50 and 50 in a freely rolling manner. Then, flange portions 52 each having an inward flange shape are provided at both axial ends of the outer ring 49,
By providing 52, the needles 50, 50 and the retainer 51 are prevented from coming off in the axial direction of the outer ring 49 (the left-right direction in FIGS. 1 and 2). Also, the guide pin 3
2a has a large-diameter portion 53 at an intermediate portion, a small-diameter portion 54 at both ends,
54 respectively. And the large diameter part 5 of these
3 is loosely inserted into the elongated oblong hole 30 and the small diameter portions 54, 54 are connected to the radial needle bearings 48, 4.
8 so as to be rotatable. When transmitting the rotational force from the driving arm 29 to the driven arm 31a,
The rotation front surface (for example, the right side surface in FIG. 1) and the rear surface in the rotation direction of one driven arm 31a (for example, the left side surface of the right driven arm 31a in FIG. 1) are in contact with each other. The above-mentioned torque is transmitted via the.

In this state, the step surfaces 55, 5 existing in a continuous portion between the large diameter portion 53 and the small diameter portions 54, 54 are provided.
5 and flanges 5 formed at both ends of the outer rings 49, 49
Of the 2, 52, minute gaps are formed between the step surfaces 55, 55 and the outer surfaces of the flanges 52, 52 on the side facing the step surfaces 55, 55, respectively. Thereby, these step surfaces 55, 55
The friction between the guide pin 32a and the flanges 52, 52 is prevented to reduce the force required for rotating the guide pin 32a. or,
When the guide pin 32a attempts to move in the axial direction (the left-right direction in FIG. 1), the step surfaces 55, 55 are brought into contact with the outer surfaces of the flanges 52, 52, and the guide pin 32a is moved. Prevents large displacements in the axial direction.
Note that both ends of the guide pin 32a are connected to the small diameter portions 54, 54.
Accordingly, the diameters of the radial needle bearings 48 supporting the small diameter portions 54 also decrease. However, in the case of the present example, since both ends of the guide pin 32a are supported by these two radial needle bearings 48, 48, these radial needle bearings 4
8, 48 load capacities can be sufficiently secured.

In the case of the swash plate type variable displacement compressor of the present embodiment configured as described above, the cooling load and the drive shaft 13 (FIG.
When the rotation speed of (6) changes and the amount of refrigerant vapor to be compressed by the compressor changes, the inclination angle of the swash plate 27 can be changed quickly. That is, when the inclination angle of the swash plate 27 is changed in order to change the amount of refrigerant vapor compressed during one rotation of the drive shaft 13 of the variable displacement compressor, the guide pin 32a moves within the oblong slot 30. In this case, the outer peripheral surface of the large diameter portion 53 of the guide pin 32a comes into rolling contact with the inner side surface of the oblique long hole 30. Therefore, the frictional force (rolling frictional force) acting on the contact portion between the outer peripheral surface of the large diameter portion 53 and the inner side surface of the inclined elongated hole 30 becomes extremely small. For example, in the case of the above-described conventional structure, the friction coefficient of the contact portion between the outer peripheral surface of the guide pin 32 and the inner surface of the inclined elongated hole 30 is 0.3 to 0.5, and the load applied to this contact portion is Because it is 100-300 kgf, 30-
A large friction force of 150 kgf acts. On the other hand, according to the structure of the present invention, the frictional force acting on the contact portion between the outer peripheral surface of the large-diameter portion 53 and the inner side surface of the inclined elongated hole 30 is changed by the friction coefficient of the needle bearings 48, 48. Is 0.001-0.
Corresponding to a low value of 005, it can be extremely reduced to 0.1 to 1.5 kgf. Therefore, this frictional force is applied to the swash plate 27.
Becomes extremely small when the inclination angle of the swash plate 27 changes, and the inclination angle of the swash plate 27 can be changed quickly (improvement of followability). As a result, when the refrigerant load or the rotation speed of the drive shaft 13 changes, the amount of refrigerant vapor compressed by the compressor for each rotation of the drive shaft can be changed quickly. Therefore, if an air conditioner for a vehicle is constituted by a vapor compression refrigerator incorporating the swash plate type variable displacement compressor of the present embodiment, the temperature in the vehicle compartment can be stably controlled.

Next, FIG. 3 corresponds to claims 1 and 3.
9 shows a second example of the embodiment of the present invention. In the case of this example, the guide pin 32 is formed in a straight shape whose diameter does not change over substantially the entire length. The guide pins 32 are non-rotatably supported by press-fitting both ends of the guide pins 32 into circular holes 47 formed at the distal ends of the driven arms 31a. A radial needle bearing 48 similar to that of the above-described first example is supported at a portion of the intermediate portion of the guide pin 32 which is inserted into the oblong slot 30. In this state, the inner side surfaces of the driven arms 31a, 31a (the surface facing the driving arm 29) and the two flange portions 52, 52 formed on both ends of the outer ring 49 of the radial needle bearing 48 are provided. A minute gap is formed between the outer surface and the outer surface. Thereby, each of the driven arms 3
The swash plate 27 (FIGS. 5 and 6) about the guide pin 32 is lightly rocked by preventing the inner side surfaces of the first and the first surfaces 31a and the both side surfaces of the drive arm 29 from rubbing each other. . Further, the radial needle bearing 48 is arranged in the axial direction (FIG. 3).
(Left and right directions), the inner surfaces of the driven arms 33a, 33a and the outer surfaces of the flanges 52, 52 are brought into contact with each other, so that the radial needle bearing 48 becomes larger in the axial direction. Prevents shifting.

In the case of the swash plate type variable displacement compressor of the present embodiment configured as described above, when the guide pin 32 moves within the oblong slot 30, the radial needle bearing 48a supported at the intermediate portion of the guide pin 32 The outer peripheral surface of the outer ring 49 and the inner side surface of the inclined oblong hole 30 are in rolling contact with each other. Therefore, also in the case of this example, it is possible to reduce the resistance when the guide pin 32 moves in the oblong hole 30 and quickly change the inclination angle of the swash plate 27 (improve the followability). it can. Other configurations and operations are the same as those of the first embodiment.
This is the same as in the example.

In the present invention, an experiment similar to the experiment whose result was shown in FIG. 7 was performed using the structure of the first example shown in FIGS. According to this experiment, the temperature change time T of the refrigerant vapor sucked into the compressor 1 from the evaporator 5 was 78 (sec) in the conventional structure, but was reduced to 60 (sec) in the present invention. From these results, it is understood that the present invention can improve the followability of the swash plate 27. Although not shown, an inclined oblong hole is provided on the driven arm side, and a pair of driving arms (including a case where the tip is forked) is provided, and both ends of the guide pin are provided at the tip of the driving arm. The present invention can also be applied to a structure that supports the guide pin and engages the intermediate portion of the guide pin with the oblong slot.

[0033]

The swash plate type variable displacement compressor of the present invention is constructed and operates as described above. Therefore, when the cooling load or the rotation speed of the drive shaft changes, the compressor is compressed every rotation of the drive shaft. The amount of refrigerant vapor can be changed quickly.
As a result, it is possible to stably control the temperature by the vehicle air conditioner.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a partial sectional view showing a second example of the embodiment of the present invention.

FIG. 4 is a circuit diagram of a vapor compression refrigerator constituting the air conditioner for a vehicle.

FIG. 5 is a cross-sectional view showing a conventional variable displacement compressor in a state where a discharge amount is maximized.

FIG. 6 is a cross-sectional view similarly showing a state in which the discharge amount is minimized.

FIG. 7 is a diagram showing the results of an experiment performed to determine the following performance of the swash plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Liquid tank 4 Expansion valve 5 Evaporator 6 Casing 7 Casing main body 8 Head case 9 End plate 10 Low pressure chamber 11 High pressure chamber 12a Suction port 12b Discharge port 13 Drive shaft 14 Cylinder 15 Partition plate 16 Piston 17 Sliding shoe 18 Crank Chamber 19 Sleeve 19a Outer diameter surface 20 Support bracket 21 Compression spring 22a, 22b Radial needle bearing 23a, 23b Thrust needle bearing 24 Adjustment nut 25 Step 26 Central hole 27 Swash plate 27a Inner surface 28 Stop ring 29 Drive arm 30 Slant long hole 31 Driven arm 32, 32a Guide pin 33 Holder 34 Connecting arm 35 Spherical concave surface 36 Guide surface 37 Suction port 38 Discharge port 39 Suction valve 40 Discharge valve 41 Pressure control passage 42 Bellow 43 flow holes 44 needle 45 pressure regulating valve 46 base 47 a circular hole 48 radial needle bearing 49 outer ring 50 the needle 51 retainer 52 collar portion 53 large diameter portion 54 small diameter portion 55 stepped surface

Claims (3)

[Claims] A casing having a suction port and a discharge port; a low-pressure chamber provided in the casing and communicating with the suction port; a high-pressure chamber provided in the casing and communicating with the discharge port; A drive shaft rotatably supported on the drive shaft, a plurality of cylinders each formed substantially parallel to the drive shaft on the periphery of the drive shaft inside the casing, and axially inside each of the cylinders. A swash plate supported by the drive shaft and rotating with the drive shaft around an intermediate portion of the drive shaft, and an angle adjusting means capable of adjusting the inclination angle of the swash plate. A transmission member for transmitting a displacement of the swash plate in the axial direction of the drive shaft due to the rotation of the drive shaft to each of the pistons; and a cold member only from the low-pressure chamber to each of the cylinders. A suction valve for flowing the medium vapor and a discharge valve for flowing the refrigerant vapor only from each of the cylinders toward the high-pressure chamber, and the angle adjusting means is rotatably supported on the drive shaft together with the drive shaft. A driving arm, a driven arm fixed to a portion of the swash plate opposite to the driving arm on one surface thereof, and an inclined portion formed at a tip end of one of the driving arm and the driven arm. A pair of the driving arm and the driven arm are provided.
The other arm of the pair sandwiches the one arm from both sides, and the middle of a guide pin supporting both ends of the other arm is inserted into the front end of the other arm into the oblong slot, thereby forming the swash plate. When adjusting the inclination angle, the supporting portion of the swash plate with respect to the drive shaft is displaced in the axial direction of the drive shaft, and the intermediate portion of the guide pin is inserted into the inclined slot in the length of the inclined slot. In the swash plate type variable displacement compressor which swings the swash plate around the guide pin while moving the swash plate around the guide pin, the inner surface of the oblong slot and the cylindrical surface concentric with the guide pin are brought into rolling contact with each other. A swash plate type variable displacement compressor characterized by: 2. A rolling contact between the inner surface of the oblong slot and the outer surface of the guide pin by rotatably supporting both ends of the guide pin to the tips of a pair of arms via respective radial needle bearings. The swash plate type variable displacement compressor according to claim 1, wherein: 3. A radial needle bearing is supported on a portion of the outer peripheral surface of the intermediate portion of the guide pin that is inserted into the oblong hole,
The swash plate type variable displacement compressor according to claim 1, wherein an outer peripheral surface of an outer ring constituting the radial needle bearing is in rolling contact with an inner side surface of the oblong slot.